Poster 293: Relationship between patellar tendon length and surgical treatment for patellar tendinosis

OBJECTIVES: Patellar tendinitis is a relatively common overuse injury that typically resolves with rehabilitation alone, however if it progresses to recalcitrant patellar tendinosis (RPT), surgical intervention is typically recommended. Patella alta, which has commonly been shown to lead to patellar dislocations, has recently shown to be related to patellar tendinitis. However, the relationship between patella alta and patellar tendinosis severe enough to warrant surgical intervention is unknown. The purpose of this study was to determine the association between patellar tendon length and surgical treatment for RPT. METHODS: A cohort of 45 patients who were scheduled for surgery due to RPT, planning to receive a partial patellar tendinectomy, were retrospectively reviewed. A group of patients consented into a different study, planning to have an anterior cruciate ligament reconstruction (ACLR), were used as a control group. Exclusion criteria for the control group included previous patellar tendinosis. For both groups, the patellar tendon was measured preoperatively on a lateral radiograph with the knee in 60° of flexion, from the distal aspect of the inferior pole of the patella to the insertion site on the tibial tubercle. Other variables assessed were primary sport played and preoperative noninvolved quadriceps strength, measured isokinetically and normalized to body weight. The RPT patients were matched to the ACLR patients based on sex, height, and weight, leaving 45 patients in each group. RESULTS: Mean age for the ACLR group was 26.0 ± 10.6 years and 25.1 ± 10.6 years for the RPT group. The groups had similar mean height (ACLR 70.2”, RPT 70.9”) and weight (ACLR 183.0 lbs, RPT 179.0 lbs), along with identical sex distribution with both having 71% males. Patients in the RPT group had statistically significantly longer patellar tendon lengths at 57.6 ± 7.4 mm compared to the ACLR group at 46.1 ± 7.5 mm, p<.001. The most frequent sports played for those in the RPT group were basketball (38%) and volleyball (22%); whereas for the ACLR group, it was basketball (22%) and football (20%). Those in the RPT group were not found to have a statistically significantly higher distribution of any individual sport played, however when the jumping sports of basketball and volleyball were combined, the RPT group showed a statistically significantly higher distribution of patients playing these sports compared to the ACLR group (60% vs 31%, p=.006). Isokinetic quadriceps strength failed to show a statistically significant difference between groups, p=.358. CONCLUSIONS: After taking into account sex, height, and weight, patients scheduled for surgery due to RPT had longer patellar tendons compared to those without a history of patellar tendinosis. Patients with RPT are also more likely to play jumping sports compared to those who sustained an ACL tear. Those with longer than normal patellar tendons who are diagnosed with patellar tendinitis, before it progresses to RPT, should consider rehabilitation and tailor their workload to avoid symptom progression and ultimately surgery.